The present invention relates to a digital photographing apparatus, a method of controlling the same, and a recording medium storing a program to implement the method, and more particularly, to a digital photographing apparatus capable of effectively reducing generation of smears during moving image capturing or moving image display, a method of controlling the digital photographing apparatus, and a recording medium storing a program to implement the method.
Generally, a digital photographing apparatus acquires data from light incident upon an imaging device and stores the data into a storage medium or displays the data as an image on a display unit. In particular, recent digital photographing apparatuses may display live view images, which may be called real-time moving images, on a display unit, or may capture moving images and store the moving images into a storage medium or display the moving images on the display unit. For convenience, “capturing moving images” is herein defined to include the meaning of “displaying live view images on a display unit”.
FIG. 1 is a pictorial diagram schematically illustrating generation of a smear during display of a moving image on a display unit of a conventional digital photographing apparatus. Referring to FIG. 1, when the conventional digital photographing apparatus displays a currently or previously captured moving image on the display unit, a strip that may be due to a smear is generated vertically if a highly luminous subject, such as the sun or a window on a building reflecting sunlight, is included among photographed subjects. To address this problem, a method in which an imaging device includes an optical black area has been proposed.
FIGS. 2 and 3 are pictorial diagrams schematically illustrating an image device. The imaging device has an effective area EA and an optical black area OBA. The optical black area OBA and the effective area EA have the same light-receiving element. However, light is incident upon the effective area EA, whereas light is not incident upon the optical black area OBA. If a highly luminous subject is photographed during moving picture photographing, relatively excessive amounts of charges are generated by a light receiving element in a portion EAS where light generated from the highly luminous subject is incident, the portion EAS being a part of the effective area EA. These excessive amounts of charges are transmitted via a vertically extended transfer path and reach a corresponding portion OBAS of the optical black area OBA. Therefore, charges are detected in the corresponding portion OBAS of the optical black area OBA. Data originating from the amount of charges detected by the corresponding portion OBAS is referred to as smear data. Thus, data corresponding to a case where smear is not generated or is reduced may be acquired by subtracting smear data, which is detected in the corresponding portion OBAS of the optical black area OBA, from data produced by the light receiving element in the portion EAS of the effective area EA, upon which the light generated from the highly luminous subject is incident.
When a moving image is captured, a user may perform a photographic operation by using a fixed digital photographing apparatus or while moving the digital photographing apparatus horizontally. However, the conventional digital photographing apparatus fails to effectively prevent smears from being generated when the conventional digital photographing apparatus moves horizontally. In other words, if a user moves a digital photographing apparatus to the right while photographing a highly luminous subject, the portion EAS of the effective area EA, upon which the light generated from the highly luminous subject is incident, moves to the left, but the corresponding portion OBAS of the optical black area OBA, from which excessive charges generated before the movement of the digital photographing apparatus are detected, may not move simultaneously when the portion EAS of the effective area EA moves.
As described above, in a conventional digital photographing apparatus, the smear data, which is detected from the corresponding portion OBAS of the optical black area OBA, is subtracted from data produced by the light receiving element in the portion EAS of the effective area EA, upon which the light generated from the highly luminous subject is incident. Thus, the left side of the portion EAS of the effective area EAm is not subjected to smear correction, but the right side of the portion EAS is subjected to smear correction although smear correction should not occur. Consequently, referring to FIG. 4, in a frame image F1 whose smears are miscorrected when moving pictures are displayed on a display unit of a conventional digital photographing apparatus, there exists a smear-uncorrected portion UCA, a smear-corrected portion CA, and a smear-overcorrected portion OCA. Thus, the display unit displays a moving picture image including two strips corresponding to the portion UCA and the portion OCA, respectively.